Already traffic is more on GTL DMM via GY line that train's like YPR SC garibrath , YPR DEE Duronto ,YPR Solapur SF express and MAS - SNSI SF express can't be diverted to run via GY.with great difficulty Indian railways have worked out for rajdhani to find a suitable and convenient time to run on GY line just bcoz to run with e loco end to end.So probably it's just a matter of time for GTL Kalluru line get doubled and electrified .I think by the end of 2018 all this doubling work would be finished and electrification can expect by 2019 to be completed.And then u can expect the above train's to run on AC traction.